1. Field of the Invention
The present general inventive concept relates to a hybrid hard disk drive (HDD), and more particularly, to a hybrid HDD to select a data storage location without operating system (OS) support, and a data storage method thereof.
2. Description of the Related Art
The hybrid HDD is a data storage apparatus designed to minimize power consumption of the hybrid HDD, and improve performance by additionally installing a flash memory device, which is a non-volatile memory device with a relatively large volume such as 64 M bytes, 128M bytes, or 256 M bytes, in an existing HDD. While most read or write operations are performed in the flash memory device of the hybrid HDD, the hybrid HDD may reduce power consumption by setting a spindle motor, a voice coil motor (VCM), etc. to a power saving mode. Thus, although the power of the hybrid HDD is off, the flash memory device may store (or maintain) data as it is non-volatile.
The hybrid HDD begins to write data on a disk by waking-up a spindle motor, VCM, etc. in a power saving mode only after a memory capacity of the flash memory device reaches a certain level. A general hybrid HDD determines whether to write a predetermined data on the disk or in the flash memory device by using a non-volatile cache command (NVC) according to a Windows operating system (OS).
However, small volume HDDs such as 1.8 inch or 1.0 inch models, which are typically used in consumer electronics (CE) environments instead of a personal computer (PC) environment, should determine whether to store data on the disk or in the flash memory device to maximize performance without OS support. The CE refers to non-PC HDD applications such as a game instrument, a personal video recorder (PVR), Karaoke equipment, a MP3 player, or a media player, etc.
Generally, the flash memory device consumes less power and has faster random operation performance, but performs sequential operations at a slower rate than a HDD performs disk operations. There is no time difference when the flash memory device accesses random operations and sequential operations. But, since the disk of the HDD has a minimized seek distance in sequential operations, the disk has a shorter access time to sequential operations than the flash memory device. However, in case of a random operation of the HDD disk, a longer seek distance causes an access time to substantially increase by a unit of milliseconds.
Therefore, in order to maximize every advantage of a disk and a flash memory based on each basic feature as needed, HDD firmware requires itself to store data in an optimal storage location between a disk and a flash memory device by analyzing a pattern of write commands transferred from a host.